The present invention relates to an ultrasonic and interventional catheter and method. More particularly, the present invention relates to such a catheter which provides imaging and hemodynamic capability. Further, the invention relates to such a catheter which provides transvascular and intracardiac imaging.
Current x-ray fluoroscopy can localize radio paque devices within the cardiovascular system and outline silhouetted anatomy. Precise localization of intracardiac anatomy is not possible; e.g., directing a catheter predictably and repetitively through the same precise point within the heart.
Ultrasound (echocardiography) can be utilized to image detailed cardiac, intracardiac, and vascular anatomy. Additionally, function, hemodynamics, and visualization of blood flow is possible. Doppler echocardiography, which utilizes the physics of ultrasound frequency to determine velocity and direction of blood flow, is used to determine pressure and flow and visualize blood movement within the cardiac chambers.
Ultrasound is increasingly utilized as a substitute for cardiac catheterization.
Currently, many interventional procedures can be performed through a catheter; e.g., balloon dilation and valvuloplasty and ablation of abnormal cardiac tissue are two frequently performed procedures.
Ultrasound has recently entered into invasive applications. Transesophageal echocardiography is the most widely utilized invasive ultrasound technique. Intravascular ultrasound utilizing miniature transducers mounted on a catheter are now undergoing vigorous clinical trials. Intracardiac imaging devices have received very limited investigation.
Increasingly, therapeutic cardiac catheterization is displacing diagnostic cardiac catheterization. Thus, there is an acceptance of catheter technology as a means of altering cardiac anatomy or conduction system. Balloon angioplasty, utilization of defect closure devices, and electrical interruption of anomalous conduction pathways are now considered accepted practice. However, most of these procedures are rather gross in nature; e.g. a large balloon splitting an obstructed valve, crude devices inserted into defects, and application of thermal or electric energy to interrupt the conduction system or produce defects in septa.